Quarter	Percent
2005-01-01	52.2
2005-04-01	51.1
2005-07-01	49.4
2005-10-01	51.3
2006-01-01	52.3
2006-04-01	51.1
2006-07-01	49.4
2006-10-01	51.3
2007-01-01	52.4
2007-04-01	51.4
2007-07-01	49.9
2007-10-01	51.6
2008-01-01	52.6
2008-04-01	51.1
2008-07-01	49.9
2008-10-01	52.3
2009-01-01	53.5
2009-04-01	52.1
2009-07-01	51.0
2009-10-01	53.4
2010-01-01	54.3
2010-04-01	52.9
2010-07-01	51.6
2010-10-01	53.9
2011-01-01	54.5
2011-04-01	53.1
2011-07-01	51.8
2011-10-01	53.5
2012-01-01	54.7
2012-04-01	53.0
2012-07-01	51.7
2012-10-01	53.6
2013-01-01	54.5
2013-04-01	53.0
2013-07-01	51.8
2013-10-01	53.9
2014-01-01	54.5
2014-04-01	53.3
2014-07-01	51.8
2014-10-01	53.7
2015-01-01	54.6
2015-04-01	53.3
2015-07-01	52.0
2015-10-01	53.6
2016-01-01	54.5
2016-04-01	53.0
2016-07-01	51.7
2016-10-01	53.6
2017-01-01	54.3
2017-04-01	52.9